Technical Field
The present invention relates to surgical instruments and, in various embodiments, to surgical cutting and stapling instruments and staple cartridges therefor that are designed to cut and staple tissue.
Background
Endoscopic surgical instruments are often preferred over traditional open surgical devices since a smaller incision tends to reduce the post-operative recovery time and complications. Consequently, significant development has gone into a range of endoscopic surgical instruments that are suitable for precise placement of a distal end effector at a desired surgical site through a cannula of a trocar. These distal end effectors engage the tissue in a number of ways to achieve a diagnostic or therapeutic effect (e.g., endocutter, grasper, cutter, staplers, clip applier, access device, drug/gene therapy delivery device, and energy device using ultrasound, RF, laser, etc.).
In many endoscopic surgical applications, it is desirable to employ end effectors that are only as large as necessary to complete a particular surgical procedure. Smaller end effectors provide better visualization of the surgical site. Smaller end effectors also allow for better access and manipulation in tight spaces. Designers of such end effectors face many challenges when trying to develop small end effectors. The ability to manufacture small end effectors and, more particularly, small endocutters that are designed to cut and staple tissue is hampered by the magnitude of the actuation forces that are generally required to form lines of staples and cut tissue. Such actuation forces can also vary with the thickness and composition of the tissue being treated. For example, larger actuation forces are commonly required to cut and staple thick tissues. Whereas, the magnitude of the actuation forces required to cut and staple thinner tissues in general are smaller. Thus, many existing endocutters typically employ robust anvil closure systems and staple driving systems that are configured to accommodate a specific range of tissue thicknesses. Such devices, however, are often not well-suited for treating thinner tissues.
Prior endocutter devices also generally cut the tissue as the staples are driven and formed in the tissue on each side of the cut. While such devices are very effective for those procedures that require the tissue to be cut and fastened, they do not provide the surgeon with the option of installing fasteners without cutting tissue. Likewise, while various forms of articulating endocutters have been developed to improve access, the components generally employed in such devices must be substantial enough to accommodate structures that can generate and transmit sufficient firing and closure forces to the end effector from the handle of the device. Thus, such end effectors are often too large to effectively access tight spaces in the body.
Accordingly, there is a need for surgical cutting and stapling instruments and staple cartridge arrangements that address many of the challenges discussed above.
The foregoing discussion is intended only to illustrate some of the shortcomings present in the field of the invention at the time, and should not be taken as a disavowal of claim scope.